Section 9 Superstructures, deckhouses and bulwarks

9.1.1 Superstructures, deckhouses and bulwarks may be of single skin or sandwich construction or a combination of both.

9.1.2 Where practicable, superstructures and deckhouses are to be designed with well cambered decks and well radiused corners to build rigidity into the structure.

9.1.3 The laminate and supporting structure are to be suitably reinforced in way of stressed corners of openings, cranes, masts, derrick posts, machinery, fittings and other heavy or vibrating loads.

9.1.4 Primary stiffening members are to be continuous and substantially bracketed at their end connections to maintain continuity of structural strength.

9.1.5 Secondary stiffening members are, in general, to be continuous through supporting structures.

9.1.6 Structures subject to concentrated loads, such as pillars out of line, are to be suitably reinforced. Where concentrations of loading on one side of a stiffener may occur, the stiffener is to be adequately stiffened against torsion. Additional reinforcements may be required in way of localised areas of high stress.

9.1.7 Structures are to comply with the minimum thickness requirements of Pt 8, Ch 3, 2 Minimum thickness requirements.

9.1.8 Where a superstructure is fitted, the side shell plating, in way of the end of the superstructure, may be required to be increased in thickness, see Pt 8, Ch 3, 3.14 Local reinforcement.

9.2.1 The term `house' is used in this Section to include both superstructures and deckhouses.

9.2.2 The symbols for use within this Section are as defined in Pt 8, Ch 3, 1.5 Symbols and definitions 1.5.1, unless otherwise specified.

9.3.1 The bending moment assumed to be carried by the house side plating is to be not less than that determined from Pt 8, Ch 3, 1.9 Plate and sandwich laminates 1.9.1, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate. This bending moment is to be applied to laminates of both single skin and sandwich construction in the determination of the panel scantling required by Pt 8, Ch 3, 9.3 House side laminates 9.3.2 and Pt 8, Ch 3, 9.3 House side laminates 9.3.4 respectively.

9.3.2 An estimate of the thickness of house side single skin plating is to be determined from Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.1. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.3 and Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.4, see also LR's Guidance Notes for Calculation Procedures for Composite Construction. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.3.3 In no case is the minimum thickness of single skin plating to be taken as less than 2,5 mm.

9.3.4 An estimate of the stiffness E , thickness of single skin plating for outer and inner skins of the house side sandwich panels and the thickness of core material is to be determined from Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.2 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.9 respectively. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.7 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.8. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.3.5 The amount of reinforcement in laminates that form the skins of a sandwich laminate is to comply with the requirements of Pt 8, Ch 3, 2.5 Minimum skin reinforcement in sandwich laminates 2.5.1.

9.4.1 The bending moment assumed to be carried by the house front plating is to be not less than that determined from Pt 8, Ch 3, 1.9 Plate and sandwich laminates 1.9.1, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate. This bending moment is to be applied to laminates of both single skin and sandwich construction in the determination of the panel scantling required by Pt 8, Ch 3, 9.4 House front laminates 9.4.2 and Pt 8, Ch 3, 9.4 House front laminates 9.4.4 respectively.

9.4.2 An estimate of the thickness of house front single skin plating is to be determined from Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.1. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.3 and Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.4, see also LR's Guidance Notes for Calculation Procedures for Composite Construction. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.4.3 In no case is the minimum thickness of single skin plating to be taken as less than 3,0 mm.

9.4.4 An estimate of the stiffness E , the thickness of single skin plating for outer and inner skins of the house front sandwich panels and the thickness of core material is to be determined from Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.2 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.9 respectively. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.7 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.8. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.4.5 The amount of reinforcement in laminates that form the skins of a sandwich laminate is to comply with the requirements of Pt 8, Ch 3, 2.5 Minimum skin reinforcement in sandwich laminates 2.5.1.

9.5.1 The bending moment assumed to be carried by the house aft end plating is to be not less than that determined from Pt 8, Ch 3, 1.9 Plate and sandwich laminates 1.9.1, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate. This bending moment is to be applied to laminates of both single skin and sandwich construction in the determination of the panel scantling required by Pt 8, Ch 3, 9.5 House aft end laminates 9.5.2 and Pt 8, Ch 3, 9.5 House aft end laminates 9.5.4 respectively.

9.5.2 An estimate of the thickness of house aft end single skin plating is to be determined from Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.1. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.3 and Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.4, see also LR's Guidance Notes for Calculation Procedures for Composite Construction. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.5.3 In no case is the minimum thickness of single skin plating to be taken as less than 2,5 mm.

9.5.4 An estimate of the stiffness E , the thickness of single skin plating for outer and inner skins of the house aft end sandwich panels and the thickness of core material is to be determined from Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.2 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.9 respectively. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.7 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.8. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.5.5 The amount of reinforcement in laminates that form the skins of a sandwich laminate is to comply with the requirements of Pt 8, Ch 3, 2.5 Minimum skin reinforcement in sandwich laminates 2.5.1.

9.6.1 The bending moment assumed to be carried by the house top plating is to be not less than that determined from Pt 8, Ch 3, 1.9 Plate and sandwich laminates 1.9.1, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate. This bending moment is to be applied to laminates of both single skin and sandwich construction in the determination of the panel scantling required by Pt 8, Ch 3, 9.6 House top laminates 9.6.3 and Pt 8, Ch 3, 9.6 House top laminates 9.6.5 respectively.

9.6.2 An estimate of the thickness of house top single skin plating is to be determined from Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.1. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.3 and Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.4, see also LR's Guidance Notes for Calculation Procedures for Composite Construction. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.6.3 In no case is the minimum thickness of single skin plating to be taken as less than 2,5 mm.

9.6.4 An estimate of the stiffness E , the thickness of single skin plating for outer and inner skins of the house top sandwich panels and the thickness of core material is to be determined from Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.2 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.9 respectively. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.7 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.8. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.6.5 The amount of reinforcement in laminates that form the skins of a sandwich laminate is to comply with the requirements of Pt 8, Ch 3, 2.5 Minimum skin reinforcement in sandwich laminates 2.5.1.

9.7.1 The bending moment assumed to be carried by the coachroof plating is to be not less than that determined from Pt 8, Ch 3, 1.9 Plate and sandwich laminates 1.9.1, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate. This bending moment is to be applied to laminates of both single skin and sandwich construction in the determination of the panel scantling required by Pt 8, Ch 3, 9.7 Coachroof laminates 9.7.2 and Pt 8, Ch 3, 9.7 Coachroof laminates 9.7.4 respectively.

9.7.2 An estimate of the thickness of coachroof single skin plating is to be determined from Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.1. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.3 and Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.4, see also LR's Guidance Notes for Calculation Procedures for Composite Construction. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.7.3 In no case is the minimum thickness of single skin plating to be taken as less than 2,5 mm.

9.7.4 An estimate of the stiffness E , thickness of single skin plating for outer and inner skins of the coachroof sandwich panels and the thickness of core material is to be determined from Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.2 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.9 respectively. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.7 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.8. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.7.5 The amount of reinforcement in laminates that form the skins of a sandwich laminate is to comply with the requirements of Pt 8, Ch 3, 2.5 Minimum skin reinforcement in sandwich laminates 2.5.1.

9.8.1 The bending moment assumed to be carried by the machinery casing plating is to be not less than that determined from Pt 8, Ch 3, 1.9 Plate and sandwich laminates 1.9.1, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate. This bending moment is to be applied to laminates of both single skin and sandwich construction in the determination of the panel scantling required by Pt 8, Ch 3, 9.8 Machinery casing laminates 9.8.2 and Pt 8, Ch 3, 9.8 Machinery casing laminates 9.8.4 respectively.

9.8.2 An estimate of the thickness of the machinery casing single skin plating is to be determined from Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.1. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.3 and Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.4, see also LR's Guidance Notes for Calculation Procedures for Composite Construction. The allowable tensile and compressive stress limits are indicated in Table 7.3.1 Limiting stress criteria for local loading for house side plating.

9.8.3 In no case is the minimum thickness of single skin plating to be taken as less than 3,0 mm.

9.8.4 An estimate of the stiffness E , the thickness of single skin plating for outer and inner skins of the machinery casing sandwich panels and the thickness of core material is to be determined from Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.2 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.9 respectively. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.7 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.8. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.8.5 The amount of reinforcement in laminates that form the skins of a sandwich laminate is to comply with the requirements of Pt 8, Ch 3, 2.5 Minimum skin reinforcement in sandwich laminates 2.5.1.

9.9.1 The side laminate may be a continuation of the hull laminate, an integral part of the deck moulding or connected as a separate assembly. The laminate is to be the same weight as the side hull laminate at the deck edge position, and is to be increased along the connection, if fitted, to the top edge of the hull. Suitable scarfing arrangements are to be made to ensure the continuity of the effect of the sheerstrake at the break and at the upper edge of the forecastle side. The laminate is to be stiffened by sideframes carried up or they may be stopped short of the deck provided the ends are effectively built-in. Deep webs are to be fitted to ensure overall rigidity of the side laminate.

9.10.1 The Rule requirements for bending moment, shear force, shear stress and deflection for the house side primary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (a).

9.10.2 The Rule requirements for bending moment, shear force, shear stress and deflection for the house side secondary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (b). Special consideration will be given to the application of other load models subject to the structural arrangement and degree of end fixity provided.

9.10.3 The allowable tensile, compressive and shear stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading , and the span/deflection ratios indicated in Table 7.2.1 Limiting span/deflection ratio are to be complied with.

9.10.4 The geometric properties of stiffener sections are to be calculated in accordance with Pt 8, Ch 3, 1.16 Geometric properties stiffener sections using an effective width of attached plating as given in Pt 8, Ch 3, 1.7 Effective width of attached plating.

9.11.1 The Rule requirements for bending moment, shear force, shear stress and deflection for the house front primary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (a).

9.11.2 The Rule requirements for bending moment, shear force, shear stress and deflection for the house front secondary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (b). Special consideration will be given to the application of other load models subject to the structural arrangement and degree of end fixity provided.

9.11.3 The allowable tensile, compressive and shear stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading , and the span/deflection ratios indicated in Table 7.2.1 Limiting span/deflection ratio are to be complied with.

9.11.4 The geometric properties of stiffeners sections are to be calculated in accordance with Pt 8, Ch 3, 1.16 Geometric properties stiffener sections using an effective width of attached plating as given in Pt 8, Ch 3, 1.7 Effective width of attached plating.

9.12.1 The Rule requirements for bending moment, shear force, shear stress and deflection for the house aft end primary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (a).

9.12.2 The Rule requirements for bending moment, shear force, shear stress and deflection for the house aft end secondary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (b). Special consideration will be given to the application of other load models subject to the structural arrangement and degree of end fixity provided.

9.12.3 The allowable tensile, compressive and shear stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading , and the span/deflection ratios indicated in Table 7.2.1 Limiting span/deflection ratio are to be complied with.

9.12.4 The geometric properties of stiffener sections are to be calculated in accordance with Pt 8, Ch 3, 1.16 Geometric properties stiffener sections using an effective width of attached plating as given in Pt 8, Ch 3, 1.7 Effective width of attached plating.

9.13.1 The house top is to be efficiently supported by a system of transverse or longitudinal beams and girders. The span of the beams is generally not to exceed 2,4 m and the beams are to be effectively built into the house upper coamings and girders.

9.13.2 The Rule requirements for bending moment, shear force, shear stress and deflection for the house top primary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (a).

9.13.3 The Rule requirements for bending moment, shear force, shear stress and deflection for the house top secondary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (b). Special consideration will be given to the application of other load models subject to the structural arrangement and degree of end fixity provided.

9.13.4 The allowable tensile, compressive and shear stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading , and the span/deflection ratios indicated in Table 7.2.1 Limiting span/deflection ratio are to be complied with.

9.13.5 The geometric properties of stiffeners sections are to be calculated in accordance with Pt 8, Ch 3, 1.16 Geometric properties stiffener sections using an effective width of attached plating as given in Pt 8, Ch 3, 1.7 Effective width of attached plating.

9.14.1 The Rule requirements for bending moment, shear force, shear stress and deflection for the coachroof primary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (a).

9.14.2 The Rule requirements for the bending moment, shear force, shear stress and deflection for the coachroof secondary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (b). Special consideration will be given to the application of other load models subject to the structural arrangement and degree of end fixity provided.

9.14.3 The allowable tensile, compressive and shear stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading , and the span/deflection ratios indicated in Table 7.2.1 Limiting span/deflection ratio are to be complied with.

9.14.4 The geometric properties of stiffener sections are to be calculated in accordance with Pt 8, Ch 3, 1.16 Geometric properties stiffener sections using an effective width of attached plating as given in Pt 8, Ch 3, 1.7 Effective width of attached plating.

9.15.1 The Rule requirements for bending moment, shear force, shear stress and deflection for the machinery casing primary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (a).

9.15.2 The Rule requirements for bending moment, shear force, shear stress and deflection for the machinery casing secondary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (b). Special consideration will be given to the application of other load models subject to the structural arrangement and degree of end fixity provided.

9.15.3 The allowable tensile, compressive and shear stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading , and the span/deflection ratios indicated in Table 7.2.1 Limiting span/deflection ratio are to be complied with.

9.15.4 Where casing sides act as girders supporting decks over, care is to be taken that access openings do not seriously weaken the structure. Openings are to be effectively framed and reinforced if found necessary. Particular attention is to be paid to stiffening where the casing supports the funnel or exhaust uptakes.

9.15.5 Where casing stiffeners carry loads from deck transverses, girders, etc. or where they are in line with pillars below, they are to be suitably reinforced.

9.15.6 The geometric properties of stiffener sections are to be calculated in accordance with Pt 8, Ch 3, 1.16 Geometric properties stiffener sections using an effective width of attached plating as given in Pt 8, Ch 3, 1.7 Effective width of attached plating.

9.16.1 The Rule requirements for bending moment, shear force, shear stress and deflection for the forecastle primary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_Sand Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (a).

9.16.2 The Rule requirements for bending moment, shear force, shear stress and deflection for the forecastle secondary stiffeners are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (b). Special consideration will be given to the application of other load models subject to the structural arrangement and degree of end fixity provided.

9.16.3 The allowable tensile, compressive and shear stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading , and the span/deflection ratios indicated in Table 7.2.1 Limiting span/deflection ratio are to be complied with.

9.16.4 The geometric properties of stiffener sections are to be calculated in accordance with Pt 8, Ch 3, 1.16 Geometric properties stiffener sections using an effective width of attached plating as given in Pt 8, Ch 3, 1.7 Effective width of attached plating.

9.17.1 Superstructure first tier sides formed by extending the hull side structure are to be in accordance with the requirements for house fronts indicated in Pt 8, Ch 3, 9.4 House front laminates and Pt 8, Ch 3, 9.11 House front stiffeners for laminates and stiffeners respectively, but need not be taken as greater than the side structure requirements at the deck edge at the same longitudinal position.

9.18.1 Fire detection, protection and extinction requirements are given in Pt 17 Fire Protection, Detection and Extinction.

9.19.1 All openings are to be substantially framed and have well rounded corners. Arrangements are to be made to minimise the effect of discontinuities. Continuous coamings or girders are to be fitted below and above doors and similar openings.

9.19.2 Particular attention is to be paid to the effectiveness of end bulkheads when large openings for doors and windows are fitted, and also to the upper deck stiffening in way.

9.19.3 Special care is to be taken to minimise the size and number of openings in the side bulkheads in the region of the ends of houses within 0,5L _R amidships. Account is to be taken of the high vertical shear loading which may occur in these areas.

9.19.4 The requirements for closing arrangements and outfit are given in Pt 3, Ch 4 Closing Arrangements and Outfit.

9.20.1 Window openings are to be suitably framed and mullions will in general be required.

9.20.2 The scantlings of mullions are to be not less than as required for a stiffener in the same position.

9.20.3 The geometric properties of stiffener sections are to be calculated in accordance with Pt 8, Ch 3, 1.16 Geometric properties stiffener sections using an effective width of attached plating as indicated in Pt 8, Ch 3, 1.7 Effective width of attached plating, in no case is the width of effective plating to be taken greater than the distance between adjacent window openings.

9.20.4 Where significant shear forces are to be transmitted by window frames, adequate shear rigidity requires to be verified.

9.21.1 Transverse rigidity is to be maintained throughout the length of the house by means of web frames, bulkheads or partial bulkheads. Particular attention is to be paid when a superimposed tier is wider than its supporting tier and when significant loads are carried on the house top.

9.21.2 Where practicable, web frames are to be arranged in line with bulkheads below.

9.21.3 Internal bulkheads are to be fitted in line with bulkheads or deep primary stiffeners below.

9.22.1 Adequate support under the ends of houses is to be provided in the form of webs, pillars, diaphragms or bulkheads in conjunction with reinforced deck beams.

9.22.2 Special attention is to be given to the connection of the house to the deck in order to provide an adequate load distribution and avoid stress concentrations.

9.22.3 Typical design details of house/deck connections are given in LR's Guidance Notes for Structural Details.

9.23.1 Sheathing arrangements are to comply with Pt 8, Ch 3, 2.9 Sheathing.

9.24.1 Laminate and stiffener requirements may need to be determined by direct calculation where the house is of unusual design, form or proportions, see also Pt 8, Ch 3, 2.7 Novel features.

9.25.1 General requirements for bulwarks are given in Pt 3, Ch 4, 8 Bulwarks, guard rails and other means for the protection of crew.

9.25.2 The bending moment assumed to be carried by the bulwark plating is to be not less than that determined from Pt 8, Ch 3, 1.9 Plate and sandwich laminates 1.9.1, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate. This bending moment is to be applied to laminates of both single skin and sandwich construction in the determination of the panel scantling required by Pt 8, Ch 3, 9.25 Bulwarks 9.25.3 and Pt 8, Ch 3, 9.25 Bulwarks 9.25.5 respectively.

9.25.3 An estimate of the thickness of the bulwark single skin plating is to be determined from Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.1. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.3 and Pt 8, Ch 3, 1.13 Determination of properties and stresses for single skin plate laminates 1.13.4, see also LR's Guidance Notes for Calculation Procedures for Composite Construction. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.25.4 In no case is the minimum thickness of single skin plating to be taken as less than 2,5 mm.

9.25.5 An estimate of the stiffness E , thickness of single skin plating for outer and inner skins of the bulwark sandwich panels and the thickness of core material is to be determined from Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.2 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.9 respectively. The tensile and compressive stresses are to be determined for each ply of reinforcement in the proposed laminate using Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.7 and Pt 8, Ch 3, 1.14 Mechanical properties sandwich laminates 1.14.8. The allowable tensile and compressive stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading are to be complied with.

9.25.6 The amount of reinforcement in laminates that form the skins of a sandwich laminate is to comply with the requirements of Pt 8, Ch 3, 2.5 Minimum skin reinforcement in sandwich laminates 2.5.1.

9.25.7 The Rule requirements for bending moment, shear force, shear stress and deflection for the bulwark stays are to be determined from the general equations given in Pt 8, Ch 3, 1.15 Stiffeners general, using the design pressure from Pt 5, Ch 3, 3.1 Hull structures or Pt 5, Ch 4, 3.1 Hull structures for non-displacement or displacement type craft as appropriate, and the coefficients Φ_M, Φ_S and Φ_δ as indicated in Table 3.1.10 Shear force, bending moment and deflection coefficients for the load model (d).

9.25.8 The allowable tensile, compressive and shear stress limits indicated in Table 7.3.1 Limiting stress criteria for local loading , and the span/deflection ratios indicated in Table 7.2.1 Limiting span/deflection ratio are to be complied with.

9.25.9 The geometric properties of stiffener sections are to be calculated in accordance with Pt 8, Ch 3, 1.16 Geometric properties stiffener sections using an effective width of attached plating as given in Pt 8, Ch 3, 1.7 Effective width of attached plating.

9.25.10 Bulwarks should not be cut for gangway or other openings near the breaks of houses.

9.25.11 Attention is to be paid to avoid discontinuity of strength of the bulwark, particularly in way of local increases in stress and changes in height.

9.25.12  Fishing craft are to have bulwarks fitted. The bulwark may be formed as a continuation of the hull laminate, an integral part of the deck moulding or connected as a separate assembly. Where the bulwark is considered to be stressed and contributing to the global strength of the craft, the laminate weight of the bulwark is not to be less than the sheer laminate weight. In no case is the bulwark laminate weight to be taken as less than 80 per cent of the shell weight. The bulwark is to be supported by suitable stiffening which may be formed by a continuation of the side frames, or by top hat, or plate laminate stays of the same weight as the bulwark. These frames are not generally to be spaced more than two side frame spacings apart.

9.25.13 In way of gantries, trawl gallows, mooring pipes etc. the laminate in way is to be increased by 50 per cent.

9.25.14  Pilot craft are to be fitted with a suitable hand rail system adjacent to the exposed areas of the working decks and platforms and in addition these areas should have non skid surfaces. Where permitted by the Flag Administration, a suitable approved continuous safety rail system will be acceptable. Suitable operating procedures are to be in place for the trained crew.

9.26.1 The requirements for freeing arrangements are given in Pt 3, Ch 4, 9 Deck drainage.

9.27.1 The requirements for free flow area are given in Pt 3, Ch 4, 9.3 Free flow area.

9.28.1 The requirements for guard rails are given in Pt 3, Ch 4, 8.4 Guard rails.